MAKING THE MEANING CLEAR

We can understand from this verse purport how the pure devotee makes the meaning clear. If I were to just read this I would not see it. This is a perfect example. This is Uddhava remembering the activities of the Lord and relating them in ecstasy to Vidura:

"[After the end of the Battle of Kurukṣetra, the Lord said:] The abatement of the earth’s great burden, eighteen akṣauhiṇīs, has now been effected with the help of Droṇa, Bhīṣma, Arjuna and Bhīma. But what is this? There is still the great strength of the Yadu dynasty, born of Myself, which may be a more unbearable burden." SB 3.3.14

It sounds to me that the Yadu dynasty is a burden on the earth. The demonic kings have all been killed. They were a burden and now the Yadus, there were millions of them, are also a burden. That's what I hear.

But Srila Prabhupada's explanation is completely different. And after hearing His explanation I can see it. But not on my own.

"All the members of the family of Lord Kṛṣṇa were incarnations of different demigods, and they were to disappear from the surface of the earth along with the Lord. When He referred to the unbearable heaviness on the earth in connection with the Yadu dynasty, He was referring to the burden of their separation." SB 3.3.14 purport

It would be more unbearable to lose the Yadus than it was to have been ruled by the demonic kings.
There was no other way for the Yadus to disappear and return to their higher planets. They could not die a "natural death" since they were all direct expansions of the Lord Himself. So there was a mock fight.